Dissimilar brazing of Ti–15Mo–5Zr–3Al and commercially pure titanium using Ti–Cu–Ni foil
Journal
Materials
Journal Volume
14
Journal Issue
20
Date Issued
2021
Author(s)
Abstract
Dissimilar brazing of Ti–15Mo–5Zr–3Al (Ti-1553) to commercially pure titanium (CP-Ti) using Ti–15Cu–15Ni foil was performed in this work. The microstructures in different sites of the brazed joint showed distinct morphologies, which resulted from the distributions of Mo, Cu, and Ni. In the brazed zone adhered to the Ti-1553 substrate, the partitioning of Mo from the Ti-1553 into the molten braze caused the formation of stabilized β-Ti without Ti2Cu/Ti2Ni precipitates. In the CP-Ti side, the brazed joint displayed a predominantly lamellar structure, composed of the elongated primary α-Ti and β-transformed eutectoid. The decrease in the Mo concentration in the brazed zone caused the eutectoid transformation of β-Ti to Ti2Cu + α-Ti in that zone. The diffusion of Cu and Ni from the molten braze into the CP-Ti accounted for the precipitation of Ti2Cu/Ti2Ni in the transformed zone therein. The variation in the shear strength of the joints was related to the amount and distribution of brittle Ti2Ni compounds. Prolonging the brazing time, the wider transformed zone, consisting of coarse elongated CP-Ti interspersed with sparse Ti2Ni precipitates, was responsible for the improved shear strength of the joint. ? 2021 by the authors. Licensee MDPI, Basel, Switzerland.
Subjects
Dissimilar brazing
Dissolution
Eutectoid
Microstructure
Titanium alloy
Binary alloys
Joints (structural components)
Lamellar structures
Molybdenum
Titanium alloys
Brazed joint
Commercially pure titanium
Eutectoid transformation
Mo concentration
Primary α
Shears strength
Ti-Cu-Ni
Titanium (alloys)
Brazing
Type
journal article